PhD, Associate Professor V.V. Apokin¹
PhD, Associate Professor V.S. Pavlovskaya¹
Dr.Hab., Professor V.D. Povzun^1
1Surgut State University, Surgut

Keywords: functional capacity, cardiovascular system, adaptive capabilities, exercise, flight.

Background. Numerous observations of athletes flying transmeridional routes revealed diverse changes in their adaptive capabilities and functional capacity occurring when flying through several time zones, which is an additional and very substantial load [4]. They are characterized by a number of both temporal and gender-specific features, and require, in our view, a separate, detailed analysis, since these changes are not so much related to the functional capacities of the body, especially in highly-skilled athletes, as to the regulatory adjustments that help the body adapt primarily to non-specific training loads associated with the synchronization of biorhythm [2]. It is clear that the ability to make such adjustments determines the adaptive capabilities of the athlete’s body, moreover, the rate of such adjustments determines the athlete’s and coach’s sports results they are most interested in. While the physiological cost of success depends on the course of these changes since it determines the type of compensatory response and the predominant distribution of loads between the structural elements of the body and, most importantly, not only in the short but also in the long range.

Objective of the study was to assess changes in the adaptive and functional capabilities of highly-skilled athletes at latitudinal displacement.

Methods and structure of the study. We evaluated the functional state of the cardiovascular system in the male swimmers of the same age group qualified not lower than Masters of Sport right after the flight through several time zones and three weeks after their stay outside their habitual time zone. The logic and procedure of measurement are described in the study [3].

Their response to the exercise experienced was evaluated based on the selected indicators and indices that reflect the state of both adaptive capabilities and functional capacity of the cardiovascular system.

Moreover, their values can be calculated providing that there are enough data on the biological rhythm and no exercise tolerance tests are required.

The available data included: HR - heart rate, SBP - systolic and DBP - diastolic blood pressure, PP - pulse pressure, ADP - average dynamic blood pressure, SO - systolic output, CO - cardiac output. Based on the daily average values of these indicators, we calculated: Kerdo vegetative index (KVI=(1-DBP/HR)x100), index of functional changes in the circulatory system or adaptive potential (FCI=0.011HR+0.014SBP+0.008DBP+0.014A+0.009BM–0.009H–0.27), where A is age, years old; BM – body mass, kg; H - height, cm; type of self-regulation of circulation (TSC=DBP/HRх100), circulatory deficiency coefficient (CDC=DBP/HR), circulatory endurance coefficient (CE=HR/PPх10), circulatory efficiency coefficient [CEC=(SBP-DBP)хHR], Robinson index or double product (RI=HRхSBP/100) [1].

The numeric data obtained were processed using the variation statistics method with the calculation of the mean value and its error.

The results are presented in Table 1 hereunder. Due to the abundance of the digital material, the table presents the milestone results only, as the remaining data did not differ significantly from those reported.

Table 1. Changes in the functional indicators of the cardiovascular system of the highly-skilled athletes outside their geographic region and habitual time zone.

It is to be recalled that the results obtained when previously analyzing the daily biorhythms in the same group of athletes indicated that there were both urgent and extended targeted systemic changes in their biorhythms in response to the time zone offset, which is a substantial load even for trained athletes since it is almost impossible to avoid an "acute" stage of desynchronosis of bodily rhythms [3]. Although these quantitative adjustments were neither critical nor particularly pathological, they should be taken into account both in the organization of the athletes' regime during the flight and in the organization of the long-term training process. The second challenge, however, already requires an understanding of the existence, depth, and course of regulatory changes.

The functional analysis of the state of the cardiovascular system and its reaction to non-specific training loads confirmed these findings. Thus, the value of the index of functional changes, which is closely related to the main parameters of hemodynamics, did not even come close to the critical value of 2.59 for the whole period of observation, which means that there was no reduction in the adaptive capabilities in the study group at all.

Nevertheless, the functional response to current needs is not so much determined by the adaptive capabilities of the body, which is for the most part a strategic reserve. The direction of vegetative reactions is mediated by changes in the activity of the central regulatory mechanisms causing changes in the vegetative tone, which ultimately determines the selection of adequate compensatory reactions.

Thus, the level of activity of the mechanisms pumping blood through the vascular system and maintaining the heart rate is determined by the predominant activity of the sympathetic or parasympathetic divisions of the autonomic nervous system, while the type of self-regulation of the heart rate determines the bodily response to physical loads. In our case, the significant preflight predominance of parasympathetic influence, as indicated by the Kerdo index value, indicates the economical distribution of hemodynamic loads and large functional reserve.

The level of tension of the mechanisms of regulation of the cardiovascular system estimated based on the value of self-regulation of circulation, always being above 110, characterizes the vascular type, which also indicates its economization and increased functional reserves of the body, at least hemodynamics.

Unfortunately, this is probably the limit of economization, as the circulatory efficiency coefficient characterizing the circulation-related energy expenditure, which in our case indicates the onset of fatigue, remains constantly high. Fatigue may be proved by a slightly decreasing value of the endurance coefficient used to assess the level of preparedness of the cardiovascular system to physical loads. Nor is there a decrease in the circulatory deficiency coefficient, which is not critical in itself but indicative of the functional reserve depletion.

The reason for this is probably not the vegetative tone, which in our group was quite adequate for highly-skilled athletes, but a reduced aerobic capacity and, as a consequence, a reduced level of functional capacity of the body as indicated by an average value of Robinson or double product index.

Results and conclusions. The analysis of the dynamic changes in the hemodynamic indices revealed that, on the one hand, the displacement of the central regulatory mechanisms in the examined group was adequate enough to optimize the functional reserves, while the current vegetative status contributed to the economization of energy resource, thus shifting the hemodynamic load towards the vascular bed. This means that the regulatory adjustments in this group were optimal.

It should be noted, however, that the athletes' functional reserve was somewhat constrained by the low values of the maximum aerobic capacity, which were not associated with the central regulatory mechanisms. This was not due to the time offset, as during the flight, there were no significant changes in the characteristics of the biological rhythm, and therefore in the adaptive capabilities. The most probable reason was exercise, which can lead to a state known as overtraining. It is impossible to avoid exercise, so this fact should be taken into account when organizing the training process and dosing the training loads.

References

1. Apokin V.V., Povzun A.A., Povzun V.D., Usaeva N.R. Specifics of urgent adaptation of cardiovascular system in athletes at latitudinal displacement. Teoriya i praktika fiz. kultury. 2015. No. 12. pp. 81-83.
2. Apokin V.V., Povzun A.A., Povzun V.D. Hemodynamic features of adaptation to physical loads in female athletes of different age groups. Teoriya i praktika fiz. Kultury, 2019. No. 12. pp. 35-37.
3. Povzun A.A., Apokin V.V. Changes in biorhythm structure of elite swimmers at long flights. Teoriya i praktika fiz. kultury. 2012. No. 5. pp. 90-93.
4. Povzun A.A., Apokin V.V., Rodionov V.A Comparative analysis of changes in the biorhythm structure in male and female swimmers at long flights. Teoriya i praktika fiz. kultury, 2012, no. 10, pp. 89-92.

Corresponding author: apokin_vv@mail.ru

Abstract

Objective of the study was to assess changes in the adaptive and functional capabilities of highly-skilled athletes at latitudinal displacement.
Methods and structure of the study. We evaluated the functional state of the cardiovascular system in the male swimmers of the same age group qualified not lower than Masters of Sport right after the flight through several time zones and three weeks after their stay outside their habitual time zone. Their response to the exercise experienced was evaluated based on the selected indicators and indices that reflect the state of both adaptive capabilities and functional capacity of the cardiovascular system.
Results and conclusions. The analysis of the dynamics of changes in the hemodynamic indices revealed that, on the one hand, the displacement of the central regulatory mechanisms in the examined group was adequate enough to optimize the functional reserves, while the current vegetative status contributed to the economization of energy resource, thus shifting the hemodynamic load towards the vascular bed. This means that the regulatory adjustments in this group were optimal.

It should be noted, however, that the athletes' functional reserve was somewhat constrained by the low values of the maximum aerobic capacity, which were not associated with the central regulatory mechanisms. This was not due to the time offset, as during the flight, there were no significant changes in the characteristics of the biological rhythm, and therefore in the adaptive capabilities. The most probable reason was exercise, which can lead to a state known as overtraining. It is impossible to avoid exercise, so this fact should be taken into account when organizing the training process and dosing the training loads.